Overview

One of the disciplines of robotics is a mastery of building electronic hardware.
It is the combination of hardware and software when make the robot do what it
can do. This is a list in reverse chronological order of all articles which
have, as their main focus, a hardware theme.

The world it is a-changin’ as many have said. No where is this more
apparent than in the “hobby” electronics space. It used to be that one
of those plastic multi-drawer cabinets full of 74xx series TTL logic,
a few resistors, capacitors, and crystals was all you needed to create
a whole slew of interesting projects. Guess what, not any more.

Normally when you write in a “high level” language you expect the compiler to get you
reasonably close to a good solution. In this example I could not get VHDL to synthesize
a simple hex decoder without resorting to the HDL equivalent of writing in assembly
language.

On the premise that you must crawl before you can walk, this first
project was really all about learning how to use the WebPack ISE tools
rather than doing any serious learning about VHDL. However, I did manage
to learn something VHDLish in the process.

Sometimes the lessons you learn aren’t about the languages, rather
it’s about the tools. This was certainly the case with the HEX display
decoder. A simple project that took me down an interesting side road.

Design a 32 bit (8 decimal digits) counter that displays its count on
an eight digit, multiplexed LED display. The counter should count at a
rate of 10 counts/second and display a decimal point between digits 7 and
8. Use the CLOCK_10HZ and HEX_DISPLAY entities in this project. Include
the ability to optionally blank leading zeros on the display.

When I was competing in BattleBots we had a number of robots in various
weight classes. These were typically controlled with regular R/C radios
and those radios generated a standard
servo control signal. I built a small board
to convert that signal into relay activation.

The “Dino Track” was a simple one channel Radio Controlled car offered
by Radio Shack one year. During the closeout at the end of the year I
bought several from the store for $4 each to use as ‘prey’ in my robot
predator prey project. Taking it apart was quite fun.

When developing for a new architecture it is useful to have a system that
is set up to let you quickly prototype ideas. When moving on to PIC16F628
development for my speed controller and Servo Gizmo projects I needed such
a tool. I evaluated the MPLAB-ICD from Microchip
and the LAB-X3 bundle from MicroEngineering Labs.

Input devices tend to consume precious I/O pins on your projects. A
new breed of input device, the Rotary Mechanical Encoder, has come down
in price (from the high $20 each range to under $5) so that you might
consider using them. I set up a PIC program to do just that.

These are David Tait’s original materials for his 16F84 programmer. The cool
thing about the 16F84 was that it had an EEPROM in it and could be reprogramed
without erasing via a UV light. Now of course every chip is programmed with
flash memory and UV lights have faded away.

Everything you needed to know about inexpensive hobby servos. These
servos are used in a variety of robot projects, from the BoeBot to
robotic arms. fortunately they are all constructed along similar lines
and use a similar signaling mechanism.

This article was pretty famous for a while. Basically I built an electronic
speed controller, like the ones used in R/C models, based on a PIC and four
transistors. It has been copied many times, when I re-visited the topic I
did so with the ServoGizmo.